documented Set/GetLabel() treatment of mnemonics

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36436 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/control.tex

@@ -35,6 +35,9 @@ Simulates the effect of the user issuing a command to the item. See \helpref{wxC
 
 Returns the control's text.
 
+Note that the returned string contains the mnemonics (\texttt{\&} characters) if
+any.
+
 
 \membersection{wxControl::SetLabel}\label{wxcontrolsetlabel}
 
@@ -42,3 +45,10 @@ Returns the control's text.
 
 Sets the item's text.
 
+The \texttt{\&} characters in the \arg{label} are special and indicate that the
+following character is a mnemonic for this control and can be used to activate
+it from the keyboard (typically by using \textit{Alt} key in combination with
+it). To insert a literal ampersand character, you need to double it, i.e. use 
+\texttt{"\&\&"}.
+
+